Burglar-alarm.



A. P. DICK, JR.

BURGLAB ALARM.

APPLICATION FILED MAY28,1013.

1,107,767. Patented Aug. 18, 19m

2% 14 wow UNITED STATES PATENT OFFICE.

ARCHIE P. 'DICK, JP, OF CLARKSVILLE, TEXAS.

BURGLAR-ALARM.

To aZZ whom it may concern Be it known that I, ARCHIE P. DICK, J r., a citizen of the United States, residing at Clarksville, in the county of Red River, State of Texas have invented certain new and useful Improvements in Burglar-Alarms; and I do hereby declare the following to be a,full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in burglar alarms and has particular reference to a portable device of this character.

The principal object of the invention is to provide a simple portable device of this character which is adapted to be hung on a door knob and sound an alarm when the knob is rotated.

Other objects and advantages will be apparent from the description and with particular reference to the drawings.

In the drawings: Figure 1 is an elevation of the device attached to a door knob. Fig. 2 is an enlarged elevation of the device, the front of the cover being removed. Fig. 3 is a vertical longitudinal sectional view on the line 33 Fig. 2. Fig. 4 is a horizontal sectional View ,on the line 44 Fig. 2. Fig. 5 is a vertical longitudinal sectional view on i the line 5-5 Fig. 2 looking in the direction of the arrows. Fig. 6 is perspective view of the clip which attaches to the knob.

Referring particularly to the accompanying drawings 10 represents a base on which is attached an electric bell 11. Above the bell is mounted a box-like supporting element 12 in which is located the battery 13, and wire 14 leading from one terminal of the battery to one binding post of the bell. Secured to the post above the battery is a clip 15, in which is secured one end of a spring contact member 16, an opening being formed in the attached end of the contact member for attachment of a wire 17 which leads to the other terminal of the battery. At the other side, on the'front of the base is a similar clip 18 carrying the contact finger 19, which has an opening in its attached end for securing one end of a wire 20 which leads to the other binding post of the bell. Secured to the contact member 16, near its free end is an eye member 21 to which is attached one end of a coil spring 22. Attached to the Specification of Letters Patent.

Application filed May 28, 1913.

Patented Aug. 18, 1914. Serial No. 770,549.

other end of the spring is a fork-shaped spring clip 23 for engagement around the shank of a knob. A hook 24 is secured to the upper end of the base 10, and is adapted to be engaged over the shank of the knob to support the device.

A suitable cover 25 is detachably secured to the base to inclose the various elements above described, an opening being formed in the center of the upper end to permit the passage of the spring 22.

In the operation of the device the hook 24 is engaged over the knob shank and the clip 23 slipped on to the shank from beneath, where upon any rotary movement of the knob, increases the tension of the spring 22 and draws the contact member 16 into engagement with the finger 19 to close the circuit through the battery and the bell and cause the ringing of the latter. Any attempt to turn the knob in either direction would result in bringing thecontacts 16 and 19 together. I

The device is of simple construction and it can be quickly and easily applied to or removed from any knob, and is of such compact structure that the complete device may be readily carried about without injury to same.

It will be noted that the book 24 is secured by means of a single fastening device, so that the hook can be folded down behind the box for packing.

What is claimed is.

A portable burglar alarm comprising a base having a battery and bell mounted thereon, a pair of contacts mounted on the base and electrically connected with the battery and bell, one of the contacts being resilient and longer than the other contact, a suspending means for engagement over the shank of a door knob, a clip for embracing the shank, and a coil spring connected to the clip and to the longer contact for flexing the contact upwardly into engagement with the other contact upon partial rotation of the knob in either direction.

In testimony whereof, I affix my signature, in presence of two witnesses.

ARCHIE P. DICK, JR. Witnesses:

Jos. SUsoNG, R. H. PATRICK. 

